The present invention relates to a method of producing a ring of abrasive elements from which to form a rotary brush, in particular a brush comprising a central hub and a ring of abrasive sheet elements substantially projecting from and connected integrally to the hub.
Rings of abrasive elements of brushes of the above type are known, from Italian Patent n. 219581 filed on Feb. 23, 1990 by the present Applicant, to be formed by successively forming a number of abrasive sheet elements from reels of abrasive material in strip form, so as to form a row of side by side, equioriented sheet elements; and subsequently arranging the sheet elements in a ring about the hub, prior to connecting the sheet elements to the hub.
The sheet elements are normally arranged manually about the hub using forming jigs associated with the hub and for ensuring uniform distribution of the sheet elements.
Though used, the above known method is fairly unsatisfactory, by failing to provide for high output rates, and therefore only being suitable for small-scale production, and by failing to ensure consistent quality of the finished brushes. That is, in the interim between being arranged about and actually connected to the hub, one or more of the sheet elements may slip with respect to the others, thus resulting in loss of symmetry and impaired efficiency of the finished brush.
Moreover, the above known method is fairly expensive, by involving the use of skilled labour, and specially designed forming tools or fixtures according to the type of brush being produced.